This study is to determine peak 5HT1 a receptor occupancy of CP-361, 428 in the brain using the PET ligand WAY-100635. To determine 5HT1 a receptor occupancy of CP-361, 428 in the brain at approximately 25% of peak concentrations using the PET ligand WAY-100635. A D4 specific PET ligand is not available to measure the affinity of CP-361, 428 in the brain; thus the investigator will use the PET ligand carbonyl 11-WAY 100635 to measure 5HT1 a receptors in the brain. This is reasonable because CP-361, 428 has similar affinity for D4 and 5HT1 a receptors. The dose selected (10mg) will be administered for 7 days to mimic steady state concentrations and will provide information about the likely effectivene3ss of this dose for future studies. The third PET scan will take place 24 hours after the last dose of CP-361, 428 and is timed to provide receptor occupancy similar to a 2.5 mg dose at steady state, another dose that may be valuable in future studies.